Penetrating dense objects at high velocity

[Beach Geek]

Few personal observations...
1. Pine needles can penetrate more than 0.50" into Chicago brick. Source: my house in 1979 hurricane Fredric.
2. Cedar is not stronger pine. Take a 2x4 of each and hit it on the endgrain with a 22oz framing hammer, cedar will crush and pine will have a dent(lodgepole) or barely a mark (southern yellow).
3. Concrete comes in different strengths from 1500psi to 7000psi mix. Curbs vary, but 2500-3500psi would be reasonably.

I agree with earlier comments about a drain hole or at least a flaw where the wood is.

PS. Never thought I'd have to "shave" my house. ;)

 

[Sturk200]

If you imagine suspending the wood by a piece of thread or fishing line or something and then whacking it at adequate speed with a concrete slab, it doesn't seem particularly counter-intuitive to think that the wood would be made to penetrate the rock. My intuition only has trouble when I imagine having the wood like resting on the ground or something and then hurling the rock at it. The trouble is that the wood in that case would always break before it had a chance to pierce the rock. But if you suspend it in such a way that there's nothing for the wood to break against, the penetration seems much more plausible.

So maybe the asymmetry is that the concrete is sturdy enough so as not to be destroyed by the impact, whereas the wood must be given special treatment so as not to be destroyed.

 

[gjonesy]

2. Cedar is not stronger pine. Take a 2x4 of each and hit it on the endgrain with a 22oz framing hammer, cedar will crush and pine will have a dent(lodgepole) or barely a mark (southern yellow).

It really depends on what you are talking about when you say "strength" and most importantly when you say "cedar", there is western red cedar and Canadian or Alaskan cypress which is called cedar. Pine has resin channels where as cedar doesn't, there for its harder because the grain is tighter.

http://woodmonsters.com/strength-chart.html